## Summary of the Pull Request
Moves the ConPTY drawing mechanism (`VtRenderer`) to use the fine-grained `til::bitmap` individual-dirty-bit tracking mechanism instead of coarse-grained rectangle unions to improve drawing performance by dramatically reducing the total area redrawn.
## PR Checklist
* [x] Part of #778 and #1064
* [x] I work here
* [x] Tests added and updated.
* [x] I'm a core contributor
## Detailed Description of the Pull Request / Additional comments
- Converted `GetDirtyArea()` interface from `IRenderEngine` to use a vector of `til::rectangle` instead of the `SMALL_RECT` to banhammer inclusive rectangles.
- `VtEngine` now holds and operates on the `til::bitmap` for invalidation regions. All invalidation operation functions that used to be embedded inside `VtEngine` are deleted in favor of using the ones in `til::bitmap`.
- Updated `VtEngine` tracing to use new `til::bitmap` on trace and the new `to_string()` methods detailed below.
- Comparison operators for `til::bitmap` and complementary tests.
- Fixed an issue where the dirty rectangle shortcut in `til::bitmap` was set to 0,0,0,0 by default which means that `|=` on it with each `set()` operation was stretching the rectangle from 0,0. Now it's a `std::optional` so it has no value after just being cleared and will build from whatever the first invalidated rectangle is. Complementary tests added.
- Optional run caching for `til::bitmap` in the `runs()` method since both VT and DX renderers will likely want to generate the set of runs at the beginning of a frame and refer to them over and over through that frame. Saves the iteration and creation and caches inside `til::bitmap` where the chance of invalidation of the underlying data is known best. It is still possible to iterate manually with `begin()` and `end()` from the outside without caching, if desired. Complementary tests added.
- WEX templates added for `til::bitmap` and used in tests.
- `translate()` method for `til::bitmap` which will slide the dirty points in the direction specified by a `til::point` and optionally back-fill the uncovered area as dirty. Complementary tests added.
- Moves all string generation for `til` types `size`, `point`, `rectangle`, and `some` into a `to_string` method on each object such that it can be used in both ETW tracing scenarios AND in the TAEF templates uniformly. Adds a similar method for `bitmap`.
- Add tagging to `_bitmap_const_iterator` such that it appears as a valid **Input Iterator** to STL collections and can be used in a `std::vector` constructor as a range. Adds and cleans up operators on this iterator to match the theoretical requirements for an **Input Iterator**. Complementary tests added.
- Add loose operators to `til` which will allow some basic math operations (+, -, *, /) between `til::size` and `til::point` and vice versa. Complementary tests added. Complementary tests added.
- Adds operators to `til::rectangle` to allow scaling with basic math operations (+, -, *) versus `til::size` and translation with basic math operations (+, -) against `til::point`. Complementary tests added.
- In-place variants of some operations added to assorted `til` objects. Complementary tests added.
- Update VT tests to compare invalidation against the new map structure instead of raw rectangles where possible.
## Validation Steps Performed
- Wrote additional til Unit Tests for all additional operators and functions added to the project to support this operation
- Updated the existing VT renderer tests
- Ran perf check
## Summary of the Pull Request
- Changes the `IRenderEngine` interface to return a vector of values instead of just a single one. Engines that want to report one still can. Engines that want to report multiple smaller ones will be able to do so going forward.
## PR Checklist
* [x] In support of differential rendering #778
* [x] I work here.
* [x] Manually tested it still works.
* [x] Am core contributor.
## Detailed Description of the Pull Request / Additional comments
- Some of my ideas for the `DxEngine` require the ability to specify multiple smaller rectangles instead of one giant one, specifically to mitigate the case where someone refreshes just one cell in two opposite corners of the display (which currently coalesces into refreshing the entire display.)
- This is pulled out into an individual PR to make it easier to review that concept changing.
## Validation Steps Performed
- Ran the Terminal
## Summary of the Pull Request
Changes how conpty emits text to preserve line-wrap state, and additionally adds rudimentary support to the Windows Terminal for wrapped lines.
## References
* Does _not_ fix (!) #3088, but that might be lower down in conhost. This makes wt behave like conhost, so at least there's that
* Still needs a proper deferred EOL wrap implementation in #780, which is left as a todo
* #4200 is the mega bucket with all this work
* MSFT:16485846 was the first attempt at this task, which caused the regression MSFT:18123777 so we backed it out.
* #4403 - I made sure this worked with that PR before I even sent #4403
## PR Checklist
* [x] Closes#405
* [x] Closes#3367
* [x] I work here
* [x] Tests added/passed
* [n/a] Requires documentation to be updated
## Detailed Description of the Pull Request / Additional comments
I started with the following implementation:
When conpty is about to write the last column, note that we wrapped this line here. If the next character the vt renderer is told to paint get is supposed to be at the start of the following line, then we know that the previous line had wrapped, so we _won't_ emit the usual `\r\n` here, and we'll just continue emitting text.
However, this isn't _exactly_ right - if someone fills the row _exactly_ with text, the information that's available to the vt renderer isn't enough to know for sure if this line broke or not. It is possible for the client to write a full line of text, with a `\n` at the end, to manually break the line. So, I had to also add the `lineWrapped` param to the `IRenderEngine` interface, which is about half the files in this changelist.
## Validation Steps Performed
* Ran tests
* Checked how the Windows Terminal behaves with these changes
* Made sure that conhost/inception and gnome-terminal both act as you'd expect with wrapped lines from conpty
## Summary of the Pull Request
Adds support for Italics, Blinking, Invisible, CrossedOut text, THROUGH CONPTY. This does **NOT** add support for those styles to conhost or the terminal.
We will store these "Extended Text Attributes" in a `TextAttribute`. When we go to render a line, we'll see if the state has changed from our previous state, and if so, we'll appropriately toggle that state with VT. Boldness has been moved from a `bool` to a single bit in these flags.
Technically, now that these are stored in the buffer, we only need to make changes to the renderers to be able to support them. That's not being done as a part of this PR however.
## References
See also #2915 and #2916, which are some follow-up tasks from this fix. I thought them too risky for 20H1.
## PR Checklist
* [x] Closes#2554
* [x] I work here
* [x] Tests added/passed
* [n/a] Requires documentation to be updated
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* store text with extended attributes too
* Plumb attributes through all the renderers
* parse extended attrs, though we're not renderering them right
* Render these states correctly
* Add a very extensive test
* Cleanup for PR
* a block of PR feedback
* add 512 test cases
* Fix the build
* Fix @carlos-zamora's suggestions
* @miniksa's PR feedback
